Rapid exchange stent delivery system and associated components

ABSTRACT

A rapid exchange stent delivery catheter includes an inner tubular member having a proximal portion, a distal portion, a stent holding portion located adjacent the distal portion of the inner member, and a guide wire lumen extending from a proximal guide wire opening disposed distal of the proximal portion of the inner member to a distal guide wire opening disposed at a distal end of the inner member. The proximal guide wire opening has a first length. An outer tubular member is slidably disposed about the inner member. The outer member has a proximal portion, a distal portion, and a guide wire opening disposed distal of the proximal portion of the outer member. The guide wire opening of the outer member has a second length that is shorter than the first length and a guide wire ramp extends into, and is movable along the first length.

CROSS REFERENCE

This application is a continuation of co-pending U.S. application Ser.No. 12/337,151, filed Dec. 17, 2008, which is a continuation of U.S.application Ser. No. 11/525,296, filed Sep. 22, 2006, now U.S. Pat. No.7,468,053; which is a continuation of U.S. application Ser. No.11/094,401, filed Mar. 30, 2005, now U.S. Pat. No. 7,115,109; which is acontinuation of U.S. application Ser. No. 10/785,350, filed Feb. 24,2004, now U.S. Pat. No. 6,890,317; which is a continuation of U.S.application Ser. No. 10/454,269, filed Jun. 4, 2003, now U.S. Pat. No.6,723,071; which is a continuation of U.S. application Ser. No.09/808,626, filed Mar. 14, 2001, now U.S. Pat. No. 6,592,549; the entiredisclosures of which are all incorporated herein by reference.

FIELD

The present disclosure generally relates to stent delivery catheters,such as biliary stent delivery catheters. More specifically, the presentdisclosure relates to rapid exchange type stent delivery catheters fordelivering a self-expanding stent to a bodily lumen, such as the biliarytract.

BACKGROUND

Endoscopic procedures for treating abnormal pathologies within thealimentary canal system and biliary tree (including the biliary,hepatic, and pancreatic ducts) are increasing in number. The endoscopeprovides access to the general area of a desired duct using directvisualization. However, the duct itself must be navigated using acatheter in conjunction with a guidewire under fluoroscopy. A widevariety of catheters are known for treatment of such targeted anatomicalregions. Examples of biliary catheters are disclosed in U.S. Pat. No.5,921,971 to Agro et al. and PCT International Publication No. 00/69498to De Toledo et al., the disclosures of which are hereby incorporated byreference.

Agro et al. '971 discloses a catheter for use in biliary procedures,wherein the catheter includes a shaft having a proximal end and a distalend. A guidewire lumen extends through the shaft from a proximalguidewire port located proximal of the distal end of the shaft, to adistal guidewire port located at the distal end of the shaft. The shaftmay also include a slot or channel extending from a proximal end of theshaft to the proximal guidewire port. Catheters incorporating such aguidewire opening and channel are often referred to as rapid exchange orsingle operator exchange type biliary catheters.

De Toledo et al. '498 discloses single operator drainage catheterdelivery system including a guide member having a guidewire lumenextending through a distal portion thereof, with a proximal guidewireport located distal of the proximal end. A placement catheter isdisposed over the guide member has a catheter lumen extending through adistal portion thereof, with a proximal guidewire port located distal ofthe proximal end. Locating the proximal guidewire ports as such allowsthe delivery system to be used by a single person with a shorterguidewire. A drainage catheter (a.k.a. a plastic stent) is disposedabout the guide member distal of the placement catheter. The drainagecatheter delivery system preferably includes a means for releasablyconnecting the placement catheter to the drainage catheter, wherein thereleasable connecting means disconnects the drainage catheter upondisplacement of the guide member. However, De Toledo et al. '498 doesnot disclose a rapid exchange biliary catheter system for the deliveryof a metallic self-expanding stent, which requires a retractable sheath.

U.S. Pat. No. 5,484,444 to Braunschweiler et al., and U.S. Pat. No.5,709,703 to Lukic et al. disclose a stent delivery device which has anelongated sheath with a self-expandable stent placed in contractedcondition within the distal area of the sheath. An elongated core isarranged in the sheath for longitudinal motion relative to the sheath tofacilitate stent delivery. However, Braunschweiler et al. '444 and Lukicet al. '703 do not provide a rapid exchange feature as in De Toledo etal. '498.

U.S. Pat. No. 5,743,874 to Fischell et al. discloses a catheter capableof performing balloon angioplasty followed by delivery of aself-expanding stent. The catheter includes an outer sheath which may bepulled back to deploy the self-expanding stent. In one embodiment, thecatheter includes a guide wire entry port located just proximal of thestent to permit rapid exchange capability. To provide the guide wireentry port, Fischell et al. '874 provides a sloped plug disposed in theinner tube and an elongate side opening in the outer sheath. Theelongate side opening in the outer sheath is necessary to permitretraction of the outer sheath for stent deployment. By providing such along side opening, a major portion of the inner workings of the catheterare exposed to bodily fluids and interference from other devices, whichmay compromise performance of the stent delivery catheter. Thisundesirable feature, in addition to others not specifically mentionedherein, leaves a need for an improved rapid exchange stent deliverycatheter.

SUMMARY

The present disclosure provides an improved rapid exchange cathetersystem for the delivery of a self-expanding stent to a bodily lumen(e.g., biliary tract, blood vessel, etc.), such as a metallic biliarystent commercially available from Boston Scientific Corporation underthe trade name Wallstent™. In an exemplary embodiment, the rapidexchange stent delivery catheter includes an inner tubular member and anouter tubular member slidably disposed thereon. The inner tubular memberhas a guide wire lumen with a proximal rapid exchange type guide wireopening. The outer tubular member also has a rapid exchange type guidewire opening that can be shorter than the guide wire lumen of the innertubular member in order to protect the inner workings of the catheterfrom bodily fluids and other devices.

The outer tubular member may include a guide wire access sleeve in whichthe guide wire opening is disposed. The guide wire access sleeve has aguide wire ramp extending into the guide wire lumen of the inner tubularmember. The guide wire sleeve may be a separate component from theremainder of the outer tubular member to facilitate efficientmanufacture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a rapid exchange stent delivery catheter systemin accordance with an exemplary embodiment of the present disclosure,shown in the delivery state;

FIG. 2 is a plan view of a distal portion of the rapid exchange stentdelivery catheter system illustrated in FIG. 1, shown in the deploymentstate;

FIG. 3 is a plan view of a distal portion of the outer tubular member ofthe rapid exchange catheter illustrated in FIG. 1;

FIG. 4 is a plan view of an inner tubular member of the rapid exchangecatheter illustrated in FIG. 1;

FIGS. 5A and 5B are cross-sectional views taken along lines 5A-5A and5B-5B, respectively, in FIG. 4;

FIG. 6 is a plan view of a self-expanding metallic stent suitable fordelivery by the rapid exchange catheter illustrated in FIG. 1;

FIG. 7A is an isometric view of a guide wire sleeve of the outer tubularmember illustrated in FIG. 3; and

FIG. 7B is a longitudinal sectional view of the guide wire sleeveillustrated in FIG. 7A.

DETAILED DESCRIPTION

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention. Those skilled in the art will recognize that the dimensionsand materials discussed herein are merely exemplary and are not intendedto limit the scope of the present invention.

Refer now to FIGS. 1 and 2 which illustrate plan views of a rapidexchange stent delivery catheter system 10 in accordance with anembodiment of the present disclosure. The rapid exchange stent deliverycatheter system 10 includes a rapid exchange catheter 100 which isadvanced over a guide wire 30 (shown in phantom) to deliver and deploy aself-expanding stent 20 in a bodily lumen.

The rapid exchange stent delivery catheter system 10 is suitable forbiliary applications and intravascular applications. In biliaryapplications, the rapid exchange stent delivery catheter system 10 issized to fit within an endoscope (not shown) and to navigate to thedesired site in the biliary tract. In vascular applications, the rapidexchange stent delivery catheter system 10 is sized to fit within anintroducer sheath (not shown) and/or a guide catheter (not shown) tonavigate to the desired vascular site.

The rapid exchange stent delivery catheter 100 includes an inner tubularmember 120 slidably disposed in an outer tubular member 140. The outertubular member 140 includes a lumen (not visible) extending therethroughto slidably accommodate the inner tubular member 120. The inner tubularmember 120 includes a guide wire lumen 130 extending through a distalportion thereof to accommodate the guide wire 30.

To provide rapid exchange capability for the rapid exchange stentdelivery catheter 100, the guide wire 30 exits through a guide wireopening 170 in the outer tubular member 140 as will be discussed ingreater detail with reference to FIGS. 3, 7A and 7B. The guide wire 30extends through a relatively short guide wire lumen and enters through adistal guide wire opening 129 in the inner tubular member 120, as willbe discussed in greater detail with reference to FIGS. 4, 5A and 5B. Inpractice, the device 100 may be inserted over the guide wire 30 from thetip end first.

A proximal handle 122 is connected to a proximal portion 124 of theinner tubular member 120. Similarly, a distal handle 142 is connected toa proximal portion 144 of the outer tubular member 140. The distalhandle 142 may be longitudinally displaced relative to the proximalhandle 122 to selectively expose or cover the self-expanding stent 20,which is disposed about a distal portion of the inner tubular member120. In FIG. 1, the distal handle 142 has been longitudinally displacedin the distal direction relative to proximal handle 122 such that theouter tubular member 140 covers the self-expanding stent 20. In FIG. 2,the distal handle 142 has been longitudinally displaced in the proximaldirection relative to proximal handle 122 to retract the outer tubularmember 140 relative to the inner tubular member 120 to expose and deploythe self-expanding stent 20.

With additional reference to FIG. 3, the outer tubular member 140includes, from the proximal end to the distal end, a proximal portion144, a main outer portion (not visible) a guide wire sleeve 160 and adistal outer portion 146. The proximal end of the proximal outer portion144 is connected to the distal handle 142. The distal handle 142 may beinjection molded over the proximal outer portion 144. The distal end ofthe proximal outer portion 144 is connected to the proximal end of themain outer portion (not visible). The distal end of the main outerportion (not visible) is connected to the proximal end of the guide wiresleeve 160, and the distal end of the guide wire sleeve 160 is connectedto the proximal end of the distal outer portion 146. The variousportions of the outer tubular member 140 may be connected by adhesive,by thermal means or by any other suitable means known to those skilledin the art.

The proximal outer portion 144 may be formed of PEBAX, having a lengthof approximately 8.0 inches (20.3 cm), an outside profile ofapproximately 0.120 inches (9 F) (0.30 cm), and an inside diameter ofapproximately 0.083 inches (0.21 cm). The guide wire sleeve 160 isdiscussed in greater detail with reference to FIGS. 7A and 7B. The mainouter portion (not visible) may be formed of PEBAX/wire braid/PTFEcomposite, having a length of approximately 55.0 inches (0.140 cm), anoutside profile of approximately 6 F (0.079 inches), and an insidediameter of approximately 0.057 inches (0.145 cm). The distal outerportion 146 may be formed of PEBAX/wire braid/PTFE composite, having alength of approximately 10.6 inches (27 cm), an outside profile ofapproximately 8 F 0.105 inches, and an inside diameter of approximately0.090 inches (0.229 cm).

A radiopaque marker band 142 may be disposed adjacent the distal end ofthe distal outer portion 146 to facilitate radiographic placement of thecatheter 100 and to radiographically indicate the position of the outertubular member 140 relative to the inner tubular member 120 to aid indeploying the self-expanding stent 20.

With additional reference to FIGS. 4, 5A and 5B, the inner tubularmember 120 includes a distal inner portion 126 connected to the distalend of the proximal inner portion 124. The proximal inner portion 124and the distal inner portion 126 are similar, except the proximal innerportion 124 can be reinforced with a SST hypotube. The inner portions124/126 may be formed of PEEK, having a length of approximately 88.6inches (225 cm), an outside profile of approximately 0.052 inches (0.13cm), and an inside diameter of approximately 0.037 inches (0.094 cm). Ajacket formed of LDPE, having a length of approximately 5.9 inches (15cm), an outside profile of approximately 0.80 inches (0.020 cm), and aninside diameter of approximately 0.055 inches (0.14 cm) may be disposedabout the inner member 120 to consume the clearance between the innermember 120 and the outer member 140 proximal of the stent 20 to preventkinking The various portions of the inner tubular member 120 may beconnected by adhesive, by thermal means or by any other suitable meansknown to those skilled in the art.

A distal head 132 is connected to the distal end of the distal innerportion 126 to limit distal displacement of the outer tubular member140. A distal bond region 134 is disposed immediately proximal of thedistal head 132. A holding sleeve 136 and a stent cup 138 preventsslippage of the stent 20. Radiopaque marker bands 44/46/48 are disposedon the distal inner portion 126 and are separated by a distanceapproximately equal to the length of the stent 20. The distal outerportion 146 of the outer tubular member 140 contains the self-expandingstent 20 during delivery.

The distal inner portion 126 includes a proximal guide wire opening 128and a distal guide wire opening 129. A guide wire lumen 130 extendsbetween the proximal guide wire opening 128 and the distal guide wireopening 129 to accommodate the guide wire 30 therein. The proximal guidewire opening 128 has a length which is greater than the length of theguide wire opening 170 of the guide wire sleeve 160. The length of theproximal guide wire opening 128 is sufficient to allow longitudinaldisplacement of the outer tubular member 140 relative to the innertubular member 120 to permit full exposure and deployment of theself-expanding stent 20. The length of the proximal guide wire opening128 is preferably slightly longer than the length of the constrainedportion of the stent 20 to avoid wedging the guide wire 30 between theinner tubular member 120 and the outer tubular member 140 prior to fulldeployment of the stent 20.

The guide wire lumen 130 may be eccentrically positioned in the distalinner portion 126 as seen in FIGS. 5A and 5B. For example, the upperwall may have a thickness of approximately 0.003 inches and the lowerwall may have a thickness of approximately 0.011 inches. The upperthinner wall portion may be removed (skived) to define the proximalguide wire opening 128. By removing only the thin-walled portion of thedistal inner portion 126, the column strength of the inner tubularmember 120 is not significantly compromised.

A solid mandrel (not shown) may be inserted into the proximal lumen (notvisible) of the inner tubular member 120 proximal of the guide wireopening 128 for improved column strength. The solid mandrel may beformed of stainless steel having an outside diameter of approximately0.030 inches with a tapered end. A stainless steel hypotube (not shown)having an outside diameter of approximately 0.079 inches may be disposedabout the proximal inner portion 124 for added column strength anddurability. The proximal handle 122 may be injection molded over theproximal end of the hypotube and the proximal end of the proximal innerportion 124.

A distal radiopaque marker 44 is disposed on the distal inner portion126 to radiographically mark the distal end of the stent 20. A proximalradiopaque marker 48 is disposed on the distal inner portion 126 toradiographically mark the proximal end of the stent 20. A mid radiopaquemarker 46 is disposed on the distal inner portion 126 distal of theholding sleeve 138 to radiographically facilitate deployment of thestent 20.

With reference to FIG. 6, the stent 20 may comprise any self-expandingstent suitable for biliary or intravascular applications. For example,in biliary applications, the self-expanding stent 20 may comprise ametallic stent commercially available from Boston Scientific Corporationunder the trade name Wallstent™.

With reference to FIGS. 7A and 7B, the guide wire sleeve 160 includes aproximal portion 164, a distal portion 162 and a lumen 166 extendingtherethrough. The distal portion 162 is flared to fit over and beconnected to the distal outer portion 146. The proximal portion 164 issized to fit within and be connected to the main outer portion.

A guide wire opening 170 extends through the exterior wall of the guidewire sleeve 160. A ramp 172 extends from the exterior wall into thelumen 166. When assembled, the ramp 172 extends through the proximalguide wire opening 128 of the inner tubular member 120 and into theguide wire lumen 130. The ramp 172 is moveable within the proximal guidewire opening 128 to facilitate a smooth transition of the guide wire 30from the guide wire lumen 130 to exterior of the catheter 100,regardless of the position of the outer tubular member 140 relative tothe inner tubular member 120.

The guide wire sleeve 160 may have a length of approximately 1.0 inch, adistal outside diameter of approximately 0.122 inches, a proximaloutside diameter of approximately 0.087 inches, a distal inside diameterof approximately 0.107 inches, and a proximal inside diameter ofapproximately 0.070 inches. The ramp 172 may be an integral extension ofthe exterior wall of the guide wire sleeve 160 and may have a length ofapproximately 0.090 inches and a width of approximately 0.50 inches. Theramp 172 may extend into the lumen 166 at an angle of approximately 30degrees to a point approximately 0.14 inches away from the oppositewall.

The guide wire sleeve 160 may be an integral part of the outer tubularmember 140 but is preferably a separately manufactured component. Forexample, the guide wire sleeve 160 may be formed of injection moldednylon or polypropylene. If the guide wire sleeve 160 is injectionmolded, manufacturing artifacts such as hole 168 may be filled orremoved depending on the particular application. By manufacturing theguide wire sleeve 160 separately, more manufacturing flexibility andefficiency are achieved. For example, the guide wire sleeve 160 may bemade of a material that is not melt sensitive or that is readily bondedto facilitate connection to other catheter components using adhesive orthermal means. In addition, the guide wire sleeve 160 may be inspectedprior entering the production floor to eliminate non-conforming partsand increase efficiency. Further, the dimensions may be controlledbetter to provide greater consistency at bond sites. These and otheradvantages not specifically mentioned herein may be obtained bymanufacturing the guide wire sleeve 160 as a separate component, butsuch is not essential to the present invention.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departures in form anddetail may be made without departing from the scope and spirit of thepresent invention as described in the appended claims.

1. (canceled)
 2. A medical device, comprising: an inner member having adistal region and an inner guidewire opening having a first length; animplant disposed about the distal region of the inner member; an outermember slidably disposed about the inner member, the outer memberincluding an outer guidewire opening having a second length differentfrom the first length; a ramp member disposed adjacent to the outerguidewire opening and extending into the inner guidewire opening; andwherein the ramp member is movable relative to the inner guidewireopening.
 3. The medical device of claim 2, wherein a solid member isdisposed within a proximal region of the inner member.
 4. The medicaldevice of claim 3, wherein the solid member is positioned proximal ofthe inner guidewire opening.
 5. The medical device of claim 3, whereinthe solid member has a tapered distal end.
 6. The medical device ofclaim 2, wherein the first length is longer than the second length. 7.The medical device of claim 2, wherein the implant includes aself-expanding stent.
 8. The medical device of claim 2, wherein theimplant includes a biliary stent.
 9. The medical device of claim 2,wherein the inner member includes a distal head.
 10. The medical deviceof claim 9, wherein a distal bonding region is disposed adjacent to thedistal head, the distal bonding region being capable of being disposedwithin the outer member.
 11. The medical device of claim 2, wherein theinner member includes a stent cup.
 12. The medical device of claim 2,wherein the outer member includes a holding sleeve.
 13. The medicaldevice of claim 12, wherein the ramp member is a portion of the holdingsleeve.
 14. A medical device, comprising: an inner tubular member havinga distal region; wherein the inner tubular member has a first guidewireopening formed therein; wherein the first guidewire opening has a firstlength; an implant disposed about the distal region of the inner tubularmember; an outer tubular member slidably disposed about the innertubular member; wherein the outer tubular member has a second guidewireopening formed therein; wherein the second guidewire opening has asecond length different from the first length; and a movable rampdisposed along the outer tubular member and extending into the firstguidewire opening.
 15. The medical device of claim 14, wherein a solidmember is disposed within a proximal region of the inner tubular memberand extends proximally from the first guidewire opening.
 16. The medicaldevice of claim 14, wherein the first length is longer than the secondlength.
 17. The medical device of claim 14, wherein the implant includesa self-expanding stent.
 18. The medical device of claim 14, wherein theouter tubular member includes a holding sleeve.
 19. The medical deviceof claim 18, wherein the movable ramp is a portion of the holdingsleeve.
 20. The medical device of claim 14, wherein the movable ramp ismovable within the first guidewire opening.
 21. A medical device,comprising: an inner tubular member having a distal region and aproximal region; wherein the inner tubular member has a first guidewireopening formed therein; wherein the first guidewire opening has a firstlength; a solid member disposed within the proximal region of the innertubular member and extending proximally from the first guidewireopening; a self-expanding stent disposed about the distal region of theinner tubular member; an outer tubular member slidably disposed aboutthe inner tubular member; wherein the outer tubular member has a secondguidewire opening formed therein; wherein the second guidewire openinghas a second length shorter than the first length; a movable rampdisposed along the outer tubular member and extending into the firstguidewire opening; and wherein the movable ramp is movable within thefirst guidewire opening.